Kistler Instrumente Ag

K.k. Holding Ag

Markus Caprez

Hans Conrad Sonderegger

Reto Calderara

Mario Giorgetta

Lothar Jahreiss

Dario Barberis

The invention concerns a sensor arrangement which is installed in the surface of carriageways or runways and serves to detect the wheel loads of vehicles or aircraft and/or their shear components on the surface during travel. The construction of the flanged tube sensor with piezoelectric crystal plates makes possible modular assembly, in that either piezo-plates sensitive to pressure P only, or to shear S, or to combinations of both are installed, since all piezo-plates have the same dimensions. The force introduction flange makes possible a concentration of the force lines onto the measuring arrangement with a substantial mechanical amplifying effect. The packing of the flanged tube sensor ready to install ensures proper fitting and positioning in the installation groove. Here the two rolling force insulation compounds and the foam insulator of the tubular part are important. The application of the invention lies in traffic management for weight detection. With the addition of shear measuring, new applications are feasible in vehicle testing tracks and aircraft landing runways, opening up new aspects of driving dynamics and security.

Sensor arrangement for installation in carriageways and runways

The invention comprises a force measuring system for the dynamic determination especially of axle loads, speed, vehicle wheelbase and gross weight. The force measuring system is laid permanently in the roadway. It is of modular assembly, consisting of the amplifier (11), sensor (12) and terminal module (13). The individual modules may be coupled tightly by plug-and-socket connections, welding flanges or glued flanges. The sensor module (12) consists of a hollow section (1), in which piezo-elements (4) are fitted under elastic preload. The piezo-elements (4) are accommodated in the hollow section (1) at intervals of typically 5 to 10 cm, and they may be connected all together with only one electrically conductive foil (5) to the signal processing facility (19), or groupwise or even singly. According to this subdivision the road width can be sectioned as desired, in order to obtain a road loading diagram for instance. The hollow section is designed so that it can be opened elastically by lateral clamping, to allow mechanically interconnected piezo-elements (4) to be inserted. After releasing this clamping, the piezo-elements (4) are under high elastic preload. In this way any tolerance errors can be overcome, so that costly machining operations are unnecessary and all parts with standard tolerances can be used.

Force sensor systems especially for determining dynamically the axle

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Zurich, Switzerland

Markus Caprez